diff --git a/components/script_bindings/webidls/TextDecoder.webidl b/components/script_bindings/webidls/TextDecoder.webidl
index cc9cf5506db..0cf8694efde 100644
--- a/components/script_bindings/webidls/TextDecoder.webidl
+++ b/components/script_bindings/webidls/TextDecoder.webidl
@@ -12,12 +12,11 @@ dictionary TextDecodeOptions {
   boolean stream = false;
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface TextDecoder {
   [Throws] constructor(optional DOMString label = "utf-8", optional TextDecoderOptions options = {});
-  readonly attribute DOMString encoding;
-  readonly attribute boolean fatal;
-  readonly attribute boolean ignoreBOM;
+
   [Throws]
   USVString decode(optional BufferSource input, optional TextDecodeOptions options = {});
 };
+TextDecoder includes TextDecoderCommon;
diff --git a/components/script_bindings/webidls/TextDecoderCommon.webidl b/components/script_bindings/webidls/TextDecoderCommon.webidl
new file mode 100644
index 00000000000..a23fb0be3f9
--- /dev/null
+++ b/components/script_bindings/webidls/TextDecoderCommon.webidl
@@ -0,0 +1,11 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+// https://encoding.spec.whatwg.org/#textdecodercommon
+
+interface mixin TextDecoderCommon {
+  readonly attribute DOMString encoding;
+  readonly attribute boolean fatal;
+  readonly attribute boolean ignoreBOM;
+};
diff --git a/components/script_bindings/webidls/TextEncoder.webidl b/components/script_bindings/webidls/TextEncoder.webidl
index 7028bb19172..44dad409969 100644
--- a/components/script_bindings/webidls/TextEncoder.webidl
+++ b/components/script_bindings/webidls/TextEncoder.webidl
@@ -9,11 +9,12 @@ dictionary TextEncoderEncodeIntoResult {
   unsigned long long written;
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface TextEncoder {
    [Throws] constructor();
-   readonly attribute DOMString encoding;
+
    [NewObject]
    Uint8Array encode(optional USVString input = "");
    TextEncoderEncodeIntoResult encodeInto(USVString source, [AllowShared] Uint8Array destination);
 };
+TextEncoder includes TextEncoderCommon;
diff --git a/components/script_bindings/webidls/TextEncoderCommon.webidl b/components/script_bindings/webidls/TextEncoderCommon.webidl
new file mode 100644
index 00000000000..de39fa3ba1b
--- /dev/null
+++ b/components/script_bindings/webidls/TextEncoderCommon.webidl
@@ -0,0 +1,9 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+// https://encoding.spec.whatwg.org/#textencodercommon
+
+interface mixin TextEncoderCommon {
+  readonly attribute DOMString encoding;
+};